Rigging Your 3D Models In The Real-World

3D Real-World Rig

Computer animation is a task both delicate and tedious, requiring the manipulation of a computer model into a series of poses over time saved as keyframes, further refined by adjusting how the computer interpolates between each frame. You need a rig (a kind of digital skeleton) to accurately control that model, and researcher [Alec Jacobson] and his team have developed a hands-on alternative to pushing pixels around.

3D Rig with Control Curves

Control curves (the blue circles) allow for easier character manipulation.

The skeletal systems of computer animated characters consists of kinematic chains—joints that sprout from a root node out to the smallest extremity. Manipulating those joints usually requires the addition of easy-to-select control curves, which simplify the way joints rotate down the chain. Control curves do some behind-the-curtain math that allows the animator to move a character by grabbing a natural end-node, such as a hand or a foot. Lifting a character’s foot to place it on chair requires manipulating one control curve: grab foot control, move foot. Without these curves, an animator’s work is usually tripled: she has to first rotate the joint where the leg meets the hip, sticking the leg straight out, then rotate the knee back down, then rotate the ankle. A nightmare.

[Alec] and his team’s unique alternative is a system of interchangeable, 3D-printed mechanical pieces used to drive an on-screen character. The effect is that of digital puppetry, but with an eye toward precision. Their device consists of a central controller, joints, splitters, extensions, and endcaps. Joints connected to the controller appear in the 3D environment in real-time as they are assembled, and differences between the real-world rig and the model’s proportions can be adjusted in the software or through plastic extension pieces.

The plastic joints spin in all 3 directions (X,Y,Z), and record measurements via embedded Hall sensors and permanent magnets. Check out the accompanying article here (PDF) for specifics on the articulation device, then hang around after the break for a demonstration video.

[Read more...]

30 Years later TED finds his voice: A Commodore Story Part I


MOS VICC II Video Interface Chip


MOS SID Chip Sound Interface Device

In the before-time (I’m talking about the 1980’s here), when home computers were considered to be consumer items, there was the Commodore C64. The C64 derived its vast array of superpowers from two Integrated Circuits (IC) named VIC and SID standing for Video Interface Chip and Sound Interface Device. Chip names were part of our culture back them, from VIC up to Fat AGNES in the end.

We spoke about VIC and SID as if they were people or distant relatives, sometimes cantankerous or prone to sudden outburst, but there was always an underlying respect for the chips and the engineers who made them. VIC and SID together made one of the world’s best video and sound experiences; movement and noise, musical notes and aliens.

[Read more...]

Developed On Hackaday: Chrome/Firefox Apps/Extensions Developers Needed

Mooltipass plugin

The Hackaday community is currently working on an offline password keeper, aka Mooltipass. The concept behind this product is to minimize the number of ways your passwords can be compromised, while generating and storing long and complex random passwords for the different websites you use daily. The Mooltipass is a standalone device connected through USB and is compatible with all major operating systems on PCs, Macs and Smartphones. More details on the encryption and technical details can be found on our github repository readme or by having look at all the articles we previously published on Hackaday.

Our beta testers are now using their prototypes daily and their feedback allowed us to considerably improve the Mooltipass. The firmware development is coming to an end as most functionalities have been implemented in the last few weeks. The development team is therefore turning his attention to the Chrome/Firefox plugins and needs your help to finish them in a timely manner. As you can guess, our goal is to provide a slick and intuitive interface for all of the Mooltipass features. If you have (a lot of) spare time, knowledge of the browsers APIs, feel free to leave a comment below with a valid email address!

Extrinsic Motivation: P = NP If You Have A Time Machine


Not all of the entries to The Hackaday Prize were serious – at least we hope not – and this one is the most entertaining of the bunch. [Eduardo] wants to put a flux capacitor in a CPU pipeline. Read that last sentence again, grab a cup of coffee, mull it over, and come back. This post will still be here.

Assuming the events portrayed in BTTF could be real in some alternate history or universe, consider the properties of a DeLorean time machine: It requires 1.21 Jiggawatts (we’re assuming this is Gigawatts from now on), has a curb weight of about three thousand pounds with the nuclear reactor and/or hovercar conversion, and is able to travel in time ± 30 years. If the power required to travel time were to scale proportionally with mass, sending a CPU register back in time would only require a Watt or so. Yes, ‘ol [Doc Brown] had it wrong with wanting to send a car back in time – sending information back is much, much easier. Now, what do you do with it?

[Eduardo] is using this to speed up pipelined CPUs. In a CPU pipeline, instructions are executed in parallel, but if one instruction depends on the output of another instruction, bad things happen CPU designers have spent long, sleepless nights figuring out how to prevent this. Basically, a MEMS flux capacitor solves all outstanding problems in CPU design. It’s brilliant, crazy, and we’re glad to see it as an entry to The Hackaday Prize.

[Eduardo], though, isn’t seeing the forest for the trees. If you have a flux capacitor in your CPU, why even bother with optimizing a CPU? Just take a normal CPU, add a flux capacitor register, and have the output of a long and complex calculation write to the time traveling register. All calculations then happen instantly, your Ps and NPs are indistinguishable. All algorithms run in O(1), and the entire endeavor is a light-hearted romp for the entire family.

SpaceWrencherThis project is an official entry to The Hackaday Prize that sadly didn’t make the quarterfinal selection. It’s still a great project, and worthy of a Hackaday post on its own.

Gaining Access to the Oculus Developer Database


One of the hackers over at Bitquark popped a shell on on the Oculus Developer Portal giving him full reign over the special admin panel inside. If he felt so inclined, this allowed him edit users, modify projects, add news articles, edit the dashboard, upload SDK files, and variety of other goodies.

The process started by using a SQL injector called BSQLi to test out parameters, cookies, and headers. Injecting into the header revealed that the Oculus team members were inserting X-Forwarded-For headers directly into the database without proper escape formatting. This got him in the door, and with a little assistance from sqlmap, the database was enumerated, and a pattern was recognized. Oculus passwords that were stored in the DB were heavily hashed. However, the user session variables remained unprotected. A SQL query was quickly built, the latest admin session was promptly extracted, and then the information was plugged in granting access to the portal. A bit more snooping around uncovered that the AJAX eval() preview script wasn’t secured by a CSRF token which could easily be exploited by a malicious hacker.

The findings were then turned into Facebook who paid the guy $15,000 for the first vulnerability plus the privilege escalation attack. $5,000 was then awarded for each subsequent SQL injection as the admin account takeover vulnerability that was found, giving the guy a nice payout for a week’s worth of work.

Homemade Activity Monitor


A group of developers have uploaded a tutorial on Instructables showing the steps needed to develop a homemade DIY fitness tracker. The design is the second iteration of an Arduino-based wearable smart watch project of theirs. This time around, they opted to focus more on the monitoring system rather than a visual display. It is called the ‘RetroBand’ and records steps taken and calories burned by the user.

The microcontroller used is an Arduino Pro mini 3.3v. Accelerometer and gyro sensors were integrated to capture the movement of the ‘RetroBand.’ A wireless bluetooth module connects to an Android phone which presents the data through a Play Store app complete with graphs included. An enclosure was 3D printed. Everything is powered by a one cell Lithum-Polymer battery. The code for the project can be found on Github, and additional information with a how-to manual is on their website (which is in Korean, but can easily be translated through the browser).

Update: 3D Printed Concrete Castle Completed

Concrete Castle

After two years of dreaming, designing, and doing, [Andrey Rudenko] has finally finished 3D printing his concrete castle. We’re sure a few readers will race to the comments to criticize the use of “castle” as an acceptable descriptor, but they’d be missing the point. It’s been only three months since he was testing the thing out in his garage, and now there’s a beautiful, freestanding structure in his yard, custom-printed.

There are no action shots of the printer setup as it lays down fat beads of concrete, only close-ups of the nozzle, but the castle was printed on-site outdoors. It wasn’t, however, printed in one piece. [Andrey] churned out the turrets separately and attached them later. He won’t be doing that again, though, because moving them in place was quite the burden. On his webpage, [Andrey] shares some insight in a wrap-up of the construction process. After much experimentation, he settled on a layer height of 10mm with a 30mm width for best results. He also discovered that he could print much more than his original estimation of 50cm of vertical height a day (fearing the lower layers would buckle).

With the castle a success, [Andrey] plans to expand his website to include a “posting wall for new ideas and findings.” We’re not sure whether that statement suggests that he would provide open-source access to everything or just feature updates of his future projects.

Wooden supports for concrete bridging.

[Andrey] used wooden supports to print concrete bridges.

We hope the former. You can check out its current format as the Architecture Forum, where he explains some of the construction capabilities and tricks used to build the castle.

His next project, a full-scale livable structure, will attempt to print 24/7 (weather permitting) rather than the stop-start routine used for the castle, which turned out to be the culprit behind imperfections in the print. He’ll have to hurry, though. [Andrey] lives in Minnesota, and the climate will soon cause construction to take a 6-month hiatus until warm weather returns. Be sure to check out his website for more photos and a retrospective on the castle project, as well as contact information—[Andrey] is reaching out to interested parties with the appropriate skills (and investors) who may want to help with the new project.

[via 3ders.org]

[Thanks Brian]


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